1. Field of the Invention
The invention relates to a pressure-tight optical cable comprising a sealing compound disposed in the region of the cable core and a pressure-resistant outside cladding surrounding the sealing compound.
2. Description of the Prior Art
An optical cable of this type is disclosed by the German Letters Patent No. 28 47 382. The outside cladding is designed two-ply, whereby a spun thread or fabric is provided as an intermediate ply whose length of lay approximately corresponds to the diameter of the cable core. A non-spaced pressure winding tightly surrounding the cable core is provided at certain intervals by shortening the length of lay.
When such cables are provided with filling compounds in their interior, difficulties result because filling compounds which have a sufficiently high modulus of elasticity and do not appreciably or completely relax are required in order to achieve a good sealing effect under higher pressures. However, filling compounds that are as soft as possible are desirable for the embedding of the light waveguides, i.e. filling compounds that have a very low modulus of elasticity and relax greatly, so that they can keep mechanical stresses of the cable away from the sensitive light waveguides to the greatest possible degree.